I want to build a Tube Preamp for my guitar, but this would be my first tube project.

The idea is to give some tone to my sound, because i have a solid state amp, but here's my question:

I've seen many preamp schematics (Marshall JCM 800 2203 or the Vox Berkeley Preamp, for example), but as they the Preamp of a Power Amp i don't know if i should use the same power supply or if they need some modifications.

I'll appreaciate any help!!!
Thanks in advance!!

(I've also posted this msg on Duncan's Amp's Forum, but no answer, i really need some help!)

Some years ago I built their Stack-In-A-Box. Their kit was pretty complete (includes a front-panel, but no case), and as I recall the directions were pretty decent. It's been a while, I forget some of the details.

I liked the sound that I got from the Stack-In-A-Box - it gives you a little tube warmth, but will not (at least with my guitar and playing style), give you loads of crunch or extreme distortion.

The single tube ( a 12 AX-7, if memory serves) died after a short life of a few months. That was my only bad experience with the kit, but better quality AX-7's are not too hard to come by.

ShiFtY, what was the secondary voltage on the power supply transformer you used for that preamp?

Its easy enough to convert from the DC voltage at the output of the diode bridge to RMS rating of the transformer secondary, but not knowing the preamps current draw, I don't know how many volts are lost in the series (22k + 10 k) resistors in the positive lead, which in turn means I don't know the voltage at the diode bridge output.

This may be something that every real tubehead knows the answer to, but I have to confess that the majority of circuits I've built have been solid-state.